Physics of ultracold Fermi gases revealed by spectroscopies

TL;DR

This review discusses how various spectroscopic techniques like RF, Bragg, and lattice modulation spectroscopy have advanced understanding of many-body quantum phenomena in ultracold Fermi gases, including superfluidity and pseudogap states.

Contribution

It provides a comprehensive overview of spectroscopic methods applied to ultracold Fermi gases and discusses their theoretical foundations and experimental insights into complex quantum states.

Findings

Insights into BCS-BEC crossover from spectroscopy

Observation of polarons and pseudogap phenomena

Measurement of contact in ultracold Fermi gases

Abstract

This article provides a brief review of how various spectroscopies have been used to investitage many-body quantum phenomena in the context of ultracold Fermi gases. In particular, work done with RF spectroscopy, Bragg spectroscopy and lattice modulation spectroscopy is considered. The theoretical basis of these spectroscopies, namely linear response theory in the many-body quantum physics context is briefly presented. Experiments related to the BCS-BEC crossover, imbalanced Fermi gases, polarons, possible pseudogap and Fermi liquid behaviour and measuring the contact are discussed. Remaining open problems and goals in the field are sketched from the perspective how spectroscopies could contribute.